1. Field of the Invention
The present invention relates to a caulking gun, and more particularly relates to an electric caulking gun that can be used conveniently.
2. Description of Related Art
With reference to FIG. 8, a conventional caulking gun comprises a caulking barrel 51, a handle 52, a pressing stem 53 and a pushing shaft 54. The caulking barrel 51 is used to hold with a caulking tube. The handle 52 is formed with a rear end of the caulking barrel 51 for a user to grip. The pressing stem 53 is pressably connected between the caulking barrel 51 and the pressing stem 52. The pushing shaft 54 is movably mounted in the caulking barrel 51 to push the caulking tube and has a unidirectional drive ring 541 and a release arm 542. The unidirectional drive ring 541 is mounted around the pushing shaft 54, presses against the pressing stem 53 to push the pushing shaft 54 to move relative to the caulking barrel 51 and to press the caulking tube by the pressing stem 53. The release arm 542 is mounted around the pushing shaft 54 and presses against the pushing shaft 54 to enable the pushing shaft 54 to move along a single direction.
The conventional caulking gun 50 can be used to make the gel flow out of the caulking tube by pressing the pressing stem 53 to enable the unidirectional drive ring 541 to move and to make the pushing shaft 54 move forward. However, the unidirectional drive ring 541 only can be moved along a single direction and the atmospheric pressure that exists out of the caulking tube cannot resist the pressing force of the immobile pushing shaft 54 to prevent the gel from flow out the caulking tube when the user releases the pressing stem 53. Then, the gel may flow out of the caulking tube after the user releasing the pressing stem 53. This may cause the working place dirty and waste the gel of the caulking tube and inconvenient in use.
To overcome the shortcomings, the present invention provides an electric caulking gun to mitigate or obviate the aforementioned problems.